Seeking the Regional Identity of Brown Propolis Produced in Southern Brazil and Linked to Total Levels of Bioactive Compounds and Biological Activity

Total levels of caffeoylquinic, p-coumaric, and benzoic acid derivatives, flavonols, and dihydroflavonols were investigated in 44 brown propolis samples from the state of Paraná (Brazil) together with their cytotoxicity and antibacterial activities. The aim was to discover chemical and biological activity-based patterns. Great quantitative variation was found within individual samples; however, a typical extract might contain 11.14–21.45 mg of caffeoylquinic acid derivatives/g, 6.27–12.17 mg of p-coumaric acid derivatives/g, 3.18–7.45 mg of benzoic acid derivatives/g, 9.35–23.55 mg of flavonols/g, and 0.17–4.25 mg of dihydroflavonols/g. MIC values poorly correlated to the levels of p-coumaric acids, flavonols, and dihydroflavonols. Most propolis samples showed medium-to-high cytotoxic activity against at least one tumoral cell. The most susceptible cell was OVCAR-8, followed by SF-295, but no correlation was found between the inhibition of OVCAR-8 and SF-295 and levels of any chemical class investigated. The concentration of bioactive compounds in brown propolis samples together with biological activities distinguished samples produced in northern, southern, eastern, and western Paraná, being characteristics associated with the geographical origin, and may help to establish a pattern for the propolis produced in the state of Paraná.